Clutch device for preventing reverse rotation.



C. A. LINDSTROM. CLUTCH DEVICE FOR PREVENTINGREVERSE ROTATION.

APPLICATION FILED SEP'I. I6. 1913.

Patented Sept. 11, 1915.

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CHARLES A. LINDSTROM, OF PITTSBURGH, PENNSYLVANIA.

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Specification of Letters Ifatent. Patented-Sept. 141, 19115.. 1

original application filed March 6, 1913, Serial No. 752,529. Divided and this application filed September 1 l 16, 1913. Serial Ito. 789,995.

, To all whom it may concern:

Be it known that I, CHARLES A. LIND- STROM, a citizen of the United States, residing at Pittsburgh, in the county of Al legheny and State of Pennsylvania, have invented a new and useful Improvement in Clutch Devices for Preventing Reverse Rotation, of which the following is a full, clear, and exact description, reference being had 1 to the accompanying drawings, forming part of this specification, in which Figure 1 is a longitudinal section of one form of clutch device embodying my invention; Fig. 2 is a section on the line IL-II of Fig. l; and Fig. 3 is a front elevation.

. My invention has relation to clutch devices of a character particularly designed for use where it is desired to permit a shaft or similar member to be freely rotated in one direction by a crank or other means, but which it is desired to positively hold against rotation in a reverse direction. One instance of such a device, where my invention is particularly applicable, is in connection with the cranking mechanism of automobiles. In such a device my invention provides means whereby the operator is protected against injury by back-firing of the engine.

The present application is, in part, a division -of my pending application, Serial N 0. 752,529, filed March 6, 1913. v

The particular nature ofthe invention will be best understood by reference to the accompanying drawings, in which I have shown the preferred embodiment thereof,

- and which will now be described, it being premised, however, that various changes may be made in the construction and ar- 40 rangement of the parts, without departing from the spirit and scope ofmy' invention as defined in the appended claims. In the drawings, the numeral 2 designates what I call the external member of the '45 clutch, which is fixed to a suitable support 3. v The external member has a circular chamber 4 therein, whose outer wall .5, forms a friction surface.

6 designates what I call the internal-' member of the clutch, consisting of a disk portion 7, having two inwardly projecting se cuts 8, which extend within the externa member, the outer surfaces of these projections being concentric with the friction surface 5 and their inner faces 9 being of irmental projections regular curved form. Said internal member also has a sleeve or hub portion 10 which is fastened to the shaft 11, and which is also fitted to receive the crank 12.

13 and 1 1 designate two friction members of similar form which are interposed between the segmental projections 8 and the friction surface 5. The outer surfaces 5 of the members 13 and 14 are intended to be forced automatically into frictional contact with the surface 5 when required.

The ends of each member 13 and 14 are formed with projections 13 and 14, having the contacting beveled surfaces 15 and 15. The friction members occupy the spaces be 7 tween the exterior of the segmental projections 8 and the interior friction surface 5, the projections 13' and 14: fitting the ends of the projections 8 and extending inwardly between said projections. One projection 13 and 14 of each member 13 and 14 is adapted for engagement with the curved surface of a cam projection 16 on the shaft '11. Said shaft has two of these cam projections arranged opposite to each other, one so of them engaging one projection 13 of one member 13 and the other en aging the pro jection 14* of the othermem er.

The shaft 11, together with the internal member, is movable longitudinally within the chamber of the external member against the action of a compression spring 17, which is seated at one end against the bearing onthe external member and at the other end against the bearing on the internal member. In order to insure the endwise movement of the members 13 and 14: with the internal member, they may be connected to the segthereof by suitable means, such as the rivets 18. The inner end W5 of theshaft 11 is formed with clutch elements 19 to engage corresponding elements 20 on the engine shaft 21.

Supposing the device to be used as the I cranking mechanism .of an automobile, the loo operation is as follows: In cranking, the

internal member is pushed inwardly against the action ofthe-compression spring 17 to 7 cause the clutchelement of the shaft 11 to;- engage the clutch elements of the engine 1 shaft 21; The crank is then rotated in the direction of the arrow in Fig. 2, the internal member and the friction members 13 and 14 rotating as a unit within the external member, because the cam projections 16 do ne not then press against the surfaces 15*, which would cause the friction members 13 and 14 to expand, but move away from them and against the inner faces 9, thus permitting the revolving of the clutch without fric-- tionalresistance between the friction surfaces. As soon as the engine starts in the right direction, the clutch elements 20 will -run ahead of the clutch elements 19 and the two members are at once separated. If the engine back-fires there is a tendency to turn the shaft member 11 in the reverse direction. Immediately this occurs, the cam projection 16 will act upon the ends 15 of the projections 13 and l4: of the friction members 13 and 14:, to force said members outwardly into locking frictional engage ment between the friction surfaces 5 and 5*. This at once locks the shaft, 11 against reverse movement, thus checking the back throw of the crank and preventing injury to the operator.

Various changes may be made in the details vof construction and arrangement of the various parts, without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A clutch device, comprising a relatively fixed external member formed with a friction surface on its inner periphery, an'

internal memberlmounted to rotate freely in one direction within the external member and also to move longitudinally with respect thereto, radially expansible; friction, elements interposed between the two members to cooperate with said internal friction surface, and an endwise movable shaftto which the internal member'is secured and which has means for expanding the friction elements when rotated in one direction, substantially as described.

2. A friction device, comprising a relatively fixed external-member, an internal member mounted to rotate freely, within said external member in one direction, and also to move longitudinally thereof, radially expansible friction devices locking the members together upon reverse rotation of the internal member, means for rotating the internal member in the free direction, and

Witnesses:

means forexpanding the friction devices to I prevent reverse rotation, substantially as described.

3. A friction-locking device, comprising two members. arranged for relative rotation and also for relative longitudinal movement, and radially expansible friction members interposed between the two 'first named members and actuated by rotary movement of one of said members'in one direction to lock the two members against relative rotation in that directiom'said friction members being idle -up on reverse relative rotation of the two members, together with spring means. interposed. between the two members, substantially. asdescribed.

4. A friction locking device, comprising a relatively fixed vexternal member having an internal peripheral friction surface, an internal member, interposed friction elements between said surface and the internal member, the internal member and the friction elements being freely rotatable in one direction with respect to the external mem her, and means for actuating the friction elements to expand them outwardly against a said internal friction surface to prevent 're verse rotation of the internal member, the internal member being also capable of longitudinal movement with'respect to the externalmember, substantially as described.

5. A device of the character described, A

wardly against said friction surface when the shaft is rotated in the reverse direction,

substantially as described.

In testimony whereof, 'I have hereunto set my hand I CHARLES A. LINDSTROM.

Gnonoa B. BLEMING, Jessa B. HELLER. 

